Here's a quick review of a little audio gadget. Digiana's AudiaX is a wireless audio FM transmitter. In short, it plugs into a headphones jack and transmits the signal over an FM frequency you choose. You can then pick up the signal with your car stereo, your Hi-Fi, or any other FM receiver. It was provided for review by Merconnet, a Canadian company based in Montreal.

It comes in a little retail pack containing the unit and a AAA battery. The coiled cord when fully stretched out is about 3 feet long. The instructions are mostly nonexistant, being entirely in Korean on the back of the pack. The English features listing and the diagram of the unit give you all the info you need, however.

On the back of the unit is a sliding door, with lock, that hides the battery compartment. The front is more interesting, because it contains the only two buttons and the LCD screen. The use of the universal symbols for Play and Stop is a little odd, given that the Stop button's main role is to turn the unit on and off. The Play button is only used to select a higher frequency, with the Stop button also being used to select a lower one. You can choose between 88.1MHz to 107.9MHz in .1MHz increments, which should be easily enough range for you to find a frequency that isn't being used in your area. The frequency is displayed on the LCD screen. It does remember your selection when the unit is turned off and turns back on at the same frequency.

So, you simply plug it into something, such as a laptop, walkman, MP3 player or similar, tune it to an appropriate frequency, tune your receiver to the same frequency and away you go. I used my laptop playing an audio CD as the source and my "boom box" portable stereo on the other side of the room as the receiver. The speakers built into the laptop are woeful, so the thought of being able to use the much better speakers in the boom box is very appealing.

The default frequency of 99.9MHz produced a loud buzzing static while the AudiaX was turned off, but as soon as I turned it on, before I even started to play the audio CD, the buzzing stopped. Clearly, the AudiaX is transmitting all the time that it is turned on. The box claims 8 hours of battery life from a normal AAA and that seems about right - after about 8 hours or so of testing, the signal began to buzz and break up. It does not turn itself off automatically, so you could waste an entire battery by leaving it on overnight. 8 hours is not very long, and if you use this regularly, perhaps in your car on the way to work each day, you'd be wise to invest in some rechargeable batteries and a charger.

The LCD screen on this unit is not particularly bright. It reminds me of the old Casio digital watch I had as a kid, with thin black lettering on the grey screen. There is a side-mounted light, again similar to an old digital watch, instead of a more modern backlit LCD. From directly ahead the screen is hard to read even with bright lighting and full batteries - tilting it to an angle makes it easier. Regardless, you only really use the screen to tune the AudiaX to the right frequency, and then to check if it's on, and to see very approximately how much battery life is left.

Usage:
Unfortunately in the radio-frequency-unfriendly environment of my computer room, the unit produced a noticeable hiss and intermittent loud static crackle. This occurred when the unit was on the other side of the room from the laptop, with various electrical devices between them, but also continued when the boom box was in the middle of the room, and even when it was placed right next to my desk, with clear air between the AudiaX and the receiving antenna. Perhaps the laptop itself is producing too much interference for the AudiaX's transmitter. Replacing the provided battery in the AudiaX with a fresh Energizer didn't fix things and neither did trying a few different frequencies.

Out in the car things were better, but not perfect. I tested with a small MP3 player and used the car's radio to pick up the signal. The music was no longer interrupted by loud static crackles, but the persistent faint hiss was still there, which wasn't heard when plugging headphones directly into the MP3 player. Trying different frequencies didn't get rid of the hiss. However, when driving along, the background noise of the car drowns out the static from the AudiaX. Sound quality in that environment seems much the same as any FM station and is received in stereo.

Conclusions:
Digiana's AudiaX has a 1-year warranty and Merconnet have it listed for USD $28.99 at the moment, which is about $41 AUD. (Edit: whoops, had Canadian pricing at first, fixed now.) Based on my experience it's difficult to recommend the AudiaX for computing-related tasks due to the crackly static issues. It did work fine in the car, despite the mild static hiss mentioned, so could be considered a cheap way to get audio from your MP3 player or PDA onto your car stereo. Perhaps what's needed is a more powerful transmitter in the AudiaX. If Digiana do re-think the design, enlarging the unit to take two batteries would be good, so it lasts longer between charges. Some kind of automatic power-off would be handy also, perhaps after the unit has been transmitting silence for 5 minutes. A way to run it from mains power or a car cigarette lighter would be useful too.